Steve, I've re-instrumented the journal-commit tests this time using the following test methodology:
Start banshee playing some classical music (mp3) Sleep 60 seconds Start firefox, open tab on a blog containing flash adverts Sleep 60 seconds Open 2nd tab on firefox on a blog with lots of images, flash videos and adverts Sleep 60 seconds Open 3rd tab on firefox on slashdot.com Sleep 60 Open 4th tab on firefox on boingboing.com Sleep 60 Start thunderbird on an IMAP gmail mailbox (note, the folders were pre-sync'd before running the test) Sleep 60 kill banshee Sleep 60 kill firefox Sleep 60 Kill thunderbird Sleep 20 This was run 5 x for two scenarios: journal-commit not enabled and journal commit enabled. I calculated the average and standard deviation. I ran this test methodology on two machines, a 64 bit Lenovo ThinkPad x220i (HDD) and a 32 bit HP mini 100 (SSD). Attached is a LibreOffice spreadsheet of the data. In both sets of tests there is no positive power saving, in fact the differences are within the the error margin of the measurements, so I can't see any positive benefit. I could re-run these tests over night on the x220i with different values for the journal commit time if you want more data, but I really suspect we won't anything much different. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/900923 Title: pm-utils: readahead and journal-commit waste power To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pm-utils/+bug/900923/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
